The Extra is Too Strong
Um Taeseong, bedridden after an accident, wakes up as Mord Vernars, a weak extra in the novel "The Magician Who Dominates the World." He uses his knowledge of the story to grow insanely powerful and change the doomed ending. Written by Kim Jaehan, illustrated by Carp Cream. Korean manhwa adapted from the web novel. Ongoing.
Read The Extra is Too Strong manhwa in English, updated regularly. Also known as: 엑스트라가 너무 강함 · Extra-ga Neomu Gangham · The Extra Is Too Powerful